What does the concept of a 'hyperplane' characterize, in general?

$3$ Points

A plane based on which most or all observations belonging to one category fall on one side, and most or ail observations belonging to another category fall on the other side.

A very large airplane used to train student pilots.

Any plane that has the same number of dimensions as the space, into which categorical observation data is defined.

Any plane that has one more dimension than the space, into which categorical observation data is defined.

$2$ Driste